Be careful _too fast or there _be an accident.A. not to drive; mustB. to not drive; mayC.

问题补充：

Be careful _too fast, or there _be an accident.

A. not to drive; must

B. to not drive; may

C. not drive; must

D. not to drive; may

答案：

A. not to drive; must

B. to not drive; may

C. not drive; must

(答案→)D. not to drive; may

解析：本题的含义是当心开车不要开得太快，否则可能会发生交通事故。Be careful not to do表示当心不要做某事的意思，动词不定式的否定形式在to do前加not，may表示可能性或许的意思，故本题选D。